The mysterious illness that has killed dozens of Cambodian children may be a deadly strain of hand, foot and mouth disease, a common childhood illness. Lab tests have confirmed that a virulent strain of the disease called EV-71 was responsible for some of the 59 cases of illness reviewed in Cambodia since April, including 52 deaths, according to the World Health Organization (WHO) and Cambodian Health Ministry.

The numbers of cases and deaths have been scaled down since an initial report put the caseload at 62. Epidemiologists are now interviewing parents and still trying to determine a cause for all the cases; in many, relevant medical information may have been omitted and not all the children were tested before they died. “As far as I’m aware, EV-71 was not identified as a virus in Cambodia before,” Dr. Nima Asgari, who is leading the WHO investigation, told the Associated Press.

The Institut Pasteur in Cambodia tested samples taken from 24 patients and found that 15 came back positive for EV-71.

EV-71 has been reported in other regions of Asia, including Vietnam and China. This strain of the disease can cause paralysis, brain swelling and death. In Cambodia, most affected children were under age 3, and many experienced severe respiratory symptoms that escalated quickly; some also developed neurological symptoms.

Hand, foot and mouth disease gets its name from a rash that appears on infected persons’ palms and soles (sometimes with blisters), along with painful, red, blister-like lesions on the tongue, gums and inside of the cheeks. Asgari told the AP that blistering was reported in only some of the Cambodian cases, but that steroids administered by doctors could have masked the symptom.

Early symptoms of hand, foot and mouth disease include fever, followed by sore throat and sometimes a poor appetite and malaise. One or two days after the fever begins, painful sores may develop in the mouth or throat, and rashes may then appear within one or two days after that. The usual incubation period — the time from infection to first symptoms — is about three to seven days.

The disease, which is caused by enteroviruses — the same family as polio — is moderately contagious and is spread through sneezing, coughing and contact with blisters or infected fecal material. Although no vaccine or specific treatment exists, the disease is typically mild and most children recover in 7 to 10 days without medical treatment, according to the Centers for Disease Control and Prevention (CDC).

The CDC notes also that children with hand, foot and mouth disease are most contagious during the first week of illness, but can continue to spread the disease long after symptoms have disappeared because the viruses that cause it can remain in the feces for weeks. Also, infected people who show no symptoms of the disease can still spread the viruses to others.

Hand, foot and mouth disease should not be confused with foot-and-mouth disease which affects cattle, sheep and swine.

Although the U.S. is not experiencing a similar outbreak, hand, foot and mouth disease can be contracted by anyone. Between November 2011 and February 2012, the CDC received reports of 63 people with symptoms of hand, foot, and mouth disease in Alabama, California, Connecticut and Nevada.

To prevent the disease, the CDC recommends:

Washing your hands often, especially after changing diapers

Thoroughly cleaning objects and surfaces (toys, doorknobs, etc.) that may be contaminated with a virus that causes the disease

Avoiding close contact (like kissing and hugging) with people who are infected